Topband: line for beverages

Jacques RAMBAUD f6bki at wanadoo.fr
Sat Jul 24 08:40:52 EDT 2004


Hello Hardy,
Thanks for the email this is amazing I bougth a roll of this military
telephone twisted line this morning to evaluate the impedance.
I wonder if other people on the list have been using it , sound the cheapest
and strongest option, I dont think the low impedance is a problem ,
transformers have to be done accordingly of course.
Other opinions are welcome.
73 Jacques F6BKI

----- Original Message ----- 
From: "RA6LBS" <ra6lbs at volgodonsk.ru>
To: "Hardy Landskov" <n7rt at cox.net>
Cc: <topband at contesting.com>
Sent: Saturday, July 24, 2004 5:05 AM
Subject: Re[2]: Topband: line for beverages


> Hi All,
>
>
> HL> The 450 ohm ladder line that everyone buys is actually by my
measurements
> HL> 374 ohm.  W8JI measured 377 ohm. We joked about it being the impedance
of
> HL> free space, 377 ohms.  But it will work in a bi-directional Beverage
> HL> application with no real receiving differences on 160.
>
> another very good solution is to use military type telephone twisted
> line which is very strong (it has some steel as well as copper stranded
> wires), holds for decades (it has UV protected coat) and its impedance
> is about 145 ohm. Works fine here and no difference at all with the
> classic open wire line.
>
> Some photos:
>
> matching unit:
> http://www.ra6lbs.ru/4271.jpg
>
> switching of the direction is done by injecting 12V into the coax line
>
>
> and the reflection transformer:
> http://www.ra6lbs.ru/4248.jpg
>
>
>
>
> -- 
> Andrei,
> RA6LBS                          mailto:ra6lbs at volgodonsk.ru
>
>                                 ICQ 342547543
>                                 www.ra6lbs.ru
>
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>





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